Pivot fan base



FIG. 1 is a top front perspective view of a new design for a pivot fan base;

FIG. 2 is a front elevation view thereof;

FIG. 3 is an enlarged right elevation view thereof with the fan rotated ninety degrees;

FIG. 4 is a greatly enlarged top plan view thereof;

FIG. 5 is a greatly enlarged bottom plan view thereof;

FIG. 6 is an enlarged left elevation view thereof with the fan rotated ninety degrees; and,

FIG. 7 is an enlarged rear perspective view thereof.

The broken line showing of a fan grill, a handle, decorative members on the fan hub, fan blades, and the fan motor is included for the purpose of illustrating environmental structure and forms no part of the claimed design. 

The ornamental design for a pivot fan base, as shown and described. 